Esters of di-hydroxy alkyl substituted xylene



2,881,150 I Patented P 195.9

United States Patent? In the formula, X is halogen or OH; R is alkyleue or arylene, e.g. methylene, ethylene, propylene, butylene,

hexylene or the like, up to 10 or more carbon atoms, ESTERS F DI-HYDROXY ALKYL SUBSTITUTED XYLENE 101 1 Jgi'uzelijki, Pittsburgh, 1:12p, assignor toPPittsburgh a e ass ompany leg my County a as in fumaric or maleic acid or phenylene, as in phthalic, notation of Pennsylvama terephthalic or isophthalic acid; Y is H or metal; and No Drawing. Application April 26, 1956 n is a whole number depending in value upon the length Serial No. 580,717 of the polyester chain.

In a related reaction, hydroxyalkoxymethyl-xylenes are 7 Claims (CL 260-454) reacted with dicarboxylic acids or anhydrides thereof to form polyesters of the generalized formula: This invention relates to polyesters of methylated aro- I matic compounds and carboxylic acids containing at least Formula B CHs- CH: CH:- CH! two carboxyl groups and to methods of preparing the where R and n have the foregoing significance.

Same- Group A may be branched or straight, alkylene, e.g. ig q g g of fliose .g i i aclds such as such as in propylene or butylene, or it may be an ether m cm am an umanc ac] containing as in the residue of diethylene or triethylene glycol. The

parenthetical chains may be of any desired length, for

H example, from 1 unit in length to 10 or more units.

a o o groups are adapted to react by addition with monomers Probably the resin compnses a mlxmre of chains of containin terminal g various lengths.

The Formulae A and B may be consolidated as groups. follows:

cm- CH2; CH? CH, X-GHr- CH: z-c-a-cr-z-cm- CH: Zt|3R-"O-Y More particularly the invention relates to polyesters where X is of a class consisting of halogen and H-Z-- derived from dihalomethyl-substituted xylenes and diwhere Z i f a class consisting of 0. carboxylic acids or the anhydrides or salts of such acids.

Halomethyl derivatives of xylene having the structure: OCH CH O-, CH CH OCH CH O- H H hi and and R is C C s a ogen CH halogen ethylemcally unsaturated and Y has the significance previously given; n is a number from about 1 to about 10.

These polyesters are valuable as resins and as plasheretofore been P p y reacting a Xylene ticizers of resins and are often characterized by ima mlxmre of xylenes with formaldehyde and a hydrogen proved resistance to the absorption of moisture. This halide, such as hydrochloric acid.

Such method is disclosed in an application to Alfred latter is a characteristic in which conventional alkyd R. Bader, Serial Number 463,801, filed October 21, 1954, resin obtained by esterification reactions between conand again in an application to Frank Fekete, Serial Numventional polyhydric alcohols, such as glycol or glycerol, fi f 1 y th t y and dicarboxylic acids (or their anhydrides) such as is inven ion comprises e iscove a 1 droxymethyl-xylenes may be reacted with dicarboxylic 60 phthahc adlplc acld male: and and the acids or their anhydrides to form valuable polyesters. are defective- Polyesters of similar character may also be formed by In the practice of the present invention various halol'eactioll P dlhalomethyl-xylefles and metal Salts 0f methyl-substituted xylenes may be employed as starting carboxyhc acids A generalized formula of the Poly materials. However, because of general cheapness and a follow esters 18 s S availability, the chloro-substituted compounds are pres- Formula A ently preferred.

OHaon. if on.- om XCHs- CH: -OCRCOCHr- CH: O -Ri -OY Forpurpos'e's of preparing alpha, alpha'-dichloro'durene, suitable for use in the practice of the present invention, a mixture is prepared comprising:

Parts by weight rn-Xylene 848 Formaldehyde (37 percent aqueous solution) 1 740 Concentrated aqueous hydrochloric acid 1800 Zinc chloride (catalyst) 40 The foregoing mixture is heated at 90 C. to 95 C. for 18 hours while hydrogen chloride gas is bubbled therethrough. The reaction mixture is cooled and a white solid is crystallized out which is filtered and washed with water, dried and crystallizedfrorn heptane to yield 869 parts by weight of 4,6-bis(chloromethyl)rn-xylene melting in arange of 93 C. to 96 C. This product is suitable for use as a-starting material in the ,preparation of polyesters in accordance withthis invention.

The foregoing compound or dihydroxymethyl-xylene derived therefrom, maybereacted with dicarboxylic acids or anhydrides to form polyesters of the type represented in Formula A (preceding). In forming the polyesters, the two reaction components, preferably are employed in approximately stoichiometric ratios.

The application of the principles of this invention to the preparation of a polyester by the direct interaction of dichloromethyl-xylene and a salt of fumaric acid is illustrated by the following example:

EXAMPLE I In this example, dimethyl formamide is employed as -a solvent. It could be replaced by other solvents such as water, though in the latter instance, the yield is somewhat impaired. The reaction mixture comprises:

Sodium fumarate grams 40 Dimethyl formamide ..milliliters 270 These are mixed and heated to 100 C. and 51 grams of dichloromethyl-Xylene are added. The mixture is refluxed for 6 hours, permitted to cool overnight, and the precipitate is filtered. The cake weighing 95 grams is washed first with water and thenwith percent solution of hydrochloric acid and" finally with water. The filtrate, when diluted with water yields an additional 18 grams of material which is subjected to the foregoing washing treatment. A total yield of 55, grams (90 percent) is obtained. The product has .a melting point in a range of 125 C. to 150 C. The saponification number is 421.5. The acidnumbenis 16.5. .The product is primarily dimethyl-alpha,alpha'-xylylene fumarate in the form of a polyester. The product is suitablefor incorporation with a monomer such as styrene, diallyl phthalate or the like to form'a resinous mixture for purposes of interpolymerization to provide a plastic material. The resinifiable mixture may be cast,.impregnated into fibrous materials, or spread upon surfaces, and then cured by baking or by being allowed to stand at room temperature.

EXAMPLE II In accordance' with this example, a mixture is prepared comprising 69 parts by weight (0.5 mol) of sodium hydrogen fumarate dissolved in 300 milliliters of dimethyl formamide. To the resultant solutionis added 51 grams (0.25 mol) of solid dichloromethyl-xylene and the mixture is refluxed for 8 hours. The resultant reaction'mixture is diluted with water to precipitate a sticky resinous material which is removed and dissolved in methyl isobutyl ketone-benzene mixture. The solution is washed with aqueous hydrochloric acid of 5 percent concentration-and then'is'washed'withwater. The residue is dried and the solvent is distilled off. A yield of'42-grams (49 percent) of a resinous polyfumarate is obtained. Upon standing, the product solidifies. The solid melts over a range of 94 C. to 120 C. The saponification number is 296 and the acid number is 98.6. This resin can' be" in a-yield'of'102 grams (98*percent).

used as an intermediate in'th'e preparation of other'resins.

EXAMPLEv III Part I A slurry comprising 71.5 grams (.375 mol) .of sodium adipate dissolved in 300 grams of dimethyl formamide is mixed with 76.5 grams (0.375 mole) of dichloromethyl-xylenetandthe mixture is heated and stirred for 10 hours at a temperature of 140' C. to 150 C. At the end of this'tim'e, theneactionaiscdeemed to be complete. The sodium chloride (45 grams) precipitated in the mixture is filtered off. The filtrate is diluted witl1.250 milliliters of -*benzene "and 500 milliliters of methyl isobutyl -ketone. The'mixture is washed'with'water'and the solvent is distilled off under vacuum while being blown with carbon dioxide. A resinous product which solidifies upon standing and melts at 55 C. to 58 C. is obtained This product has a solids content of 96.4, a saponification number of 403 as against a calculated saponification number of 405.

Part 2 In accordance withthis example, water is employed as a reaction medium-in forming-apolyester. A.solution of 62.5 grams of sodium adipate in 150 milliliters of Water is heated to C. and is treated with 65 grams of dichloromethylxylene. The mixture is refluxed for 10 hours with agitation. The resultantproduct is poured on ice, washed with water and then is mixed with-toluene. The mixture of residual water and toluene is distilled off azeotropically. The resinous product is of light color and is obtained in a yield of 60 grams (69 percent). The saponification number is 354. The solids content is 99.4 percent.

It is also possible to prepare a polyester by preliminarily hydrolyzing a dichloromethyl-xylene and then reactingthe resultant dihydroxymethyl-xylene with a dicarboxylic acid or an anhydride thereof. The hydrolysis of dichloromethyl-xylene may be conveniently conducted by heating with water, a mixture of dichloromethylxylene, sodium acetateand sodium hydroxide. The reaction procee'ds in'accor'dance with the equation:

.heatrwater (CHICDZ CH3 EXAMPLE IV 'Hydrolysis ofdichloromethyl-xylene'was conducted as follows:

A solution of 214 grams(1l5' moles)"of sodium acetate trihydrate in l00'milliliters of'water is mixed' with 75.5 grams (0.37'mole) of dichloromethyl xylene and the mixture is refiuxed with*agitation'for'lOj hours. At this point, 150 grams of 20 percent aqueous sodium hydroxide is added and the-mixture is heated with stirring until a pH value of '7 to 8-is attained. The mixture is then cooled and the product which precipitates is removed from the mother liquor by filtration.

- The productis 'washed with water and'dried. It is a white, amorphous solid which melts at 139 C. to 144 C. in a yield of 92 percent (57 grams). The product hasa hydroxyl number of 600; is substantially chlorine-free. The product can melt in a-range-of C. to 144 C. dependent upon the mixture of isomers of dichloro' methyl-xylene which are treated.

A similar method' is also applicable to thepreparation ""of'"dimethylbenzyl -alcohol. In'this operation, a solution of 400 grams (4.87 moles) of sodium acetate in 600 milliliters of water is treated with 417 grams (2.78 moles) of monochloromethyl-xylene and the mixture is refluxed for 16 hours. At this point, a solution of 112 grams (2.78 moles) of sodium hydroxide in water is added and the mixture is further refluxed for an additional 4 hours. Then the organic layer is separated and distilled. The product is obtained in a yield of 315 grams (85 percent). It boils at a temperature in a range of 90 C. to 107 C. at a pressure of 0.8 to 1 millimeter of mercury absolute). The refractive index n =1.5338. The hydroxyl number is 413 as against a calculated hydroxyl number of 412.

EXAMPLE V In accordance with this example, a polyester is prepared by reaction of dihydroxymethyl-xylene, such as is prepared by the reaction of Example IV, with a dicarboxylic acid. The charge comprises:

Maleic anhydride 122.5 grams (1.25 moles). Dihydroxymethyl-xylene 276 grams (1.67 moles). Xylene 80 grams.

The xylene is employed as an azeotropic refluxing medium. The foregoing mixture is heated at 140 C. to 165 C. until no more water can be eliminated and it is then blown with inert gas to remove any light end product. A yield of 400 grams of resinous material is obtained which has a solids content of 89.7, a saponification number of 342 as against a calculated saponification number of 348. The acid number is 13.9 and the yield is 95 percent.

This polyester is diluted with 30 percent of styrene (percent based upon the mixture). The mixture is catalyzed with 1 percent of benzoyl peroxide, and is cured at 50 C. to 120 C. for 1 hour and at 120 C. for 1 hour, to provide a hard, tough plastic. The mixture may be employed in casting or in molding powders, or in impregnating fibrous materials.

EXAMPLE VI In accordance with this example, di(beta-hydroxy ethoxymethyl)xylene is prepared as follows: a mixture of 40 grams of sodium hydroxide and 300 milliliters of ethylene glycol is heated to 140 C. to 150 C. until all of the sodium hydroxide is dissolved. While the mixture is maintained at a temperature of 150 C., 102 grams (0.5 mole) of solid dichloromethyl-xylene is added. The reaction mixture is vigorously agitated and a reaction temperature of 140 C. is maintained for 4 hours. The reaction mixture is cooled and then filtered in order to remove precipitated sodium chloride. Any excess glycol is stripped off and the residue is filtered and distilled.

A yield of 105 grams (87 percent) of a product boiling in a range of -105 C. to 205 C. at a pressure of 0.8 to 1 millimeter of mercury and having a refractive index of n =1.5307 is obtained. The product has a hydroxyl number of 428 as against a calculated number of 441. The density at 23 C. is 1.117 gram/ml., M =70.63, calculated 70.20.

EXAMPLE VII In accordance with the provisions of this example, di(beta-hydroxyethoxymethyl)xylene prepared as in Example VI is reacted with maleic anhydride to provide a polyester. The reaction mixture comprises;

Di(beta-hydroxyethoxymethyl)xylene grams 200 Maleic anhydride do 63.5 Xylene milliliters 70 The xylene constitutes an azeotropic medium for removal of water from the charge. The foregoing mixture is introduced into a three-necked flask equipped with a reflux condenser, mechanical stirrer, water separator and a gas inlet tube. The charge is heated at 165 C. to 200 C. until no more water is eliminated, the xylene is In accordance with the provisions of this example, di-

hydroxymethyl-xylene prepared as in Example IV and ethylene glycol are reacted with maleic anhydride to provide a polyester. The reaction mixture comprises:

Grams Dihydroxymethyl-xylene 170 Ethylene glycol 63 Maleic anhydride 180 Xylene 70 The reaction mixture is heated at 160 C. to 175 C. for 6 hours. Water is evolved and azeotropically removed from the reaction mixture. At the conclusions of the foregoing period, 5 milliliters of ethylene glycol are added and the heating is continued until the elimination of water has subsided. The temperature is then increased to 190 C. for 30 minutes, the resin is blown with carbon dioxide to remove light end products.

The polyester in a yield of 317 grams (92.5 percent) is a hard resin of a solids content of 98.7, a saponification number of 503 (as against a calculated saponification number of 514) and an acid number of 1.52. The resin is diluted with styrene to provide a liquid interpolymerizable mixture. The mixture can be stabilized against premature gelation by addition of 0.001 to 0.5 percent by weight of hydroquinone or t-butyl catechol. Themixture can be mixed with 1 percent of peroxidic catalyst and cured by baking at 75 C. to 250 C. to a hard, tough plastic state. The interpolymerizable mixture of poleyster and styrene is suitable for castings, for coating and for impregnating.

EXAMPLE IX fication mixture is of the following composition:

Dihydroxymethyl-xylene grams Di(beta-hydroxyethoxymethyl)xylene do Adipic acid Xylene do. 180 milliliters 100 The reaction mixture is refluxed at a temperature of C. to C. until 29.8 milliliters of water has been eliminated. At this point, a small amount (about 0.1 gram) of paratoluene sulfonic acid is added as an esterificatron catalyst and reaction is continued until a total 31.8 milliliters of water are removed or until the elimination of water has ceased.

The solvent is removed by heating and concurrently blowing the reaction mixture with carbon dioxide while the mixture is subjected to vigorous stirring until a temperature of 188 C. is attained, heating is then discontinued. Blowing with inert gas (carbon dioxide), however, is continued at an increased rate until the temperature drops to 145 C. The product is discharged at 145 C. and is then cooled.

A yield of 389 grams (94 percent) of resin is obtained. The resin is of a solids content of 99.7 percent; hydroxyl number of 157; acid number of 15.2; a saponification number of 356 (as against the calculated number of 347); the viscosity is Z and the Gardner color is 6-7,

- tion.

The resin, in an amount of about 100 parts by weight, is mixed with tolylene diisocyanate isomers in an amount of about 25 to 50 parts by Weight, a catalyst-such as N-methyl morpholine a dispersing agent such as a commercial alkaryl polyether sulfonate sold as Triton-X-ZOO, Evater, and then is reacted-40 provide a polyurethane It has previously been indicated that the interpolymers of monomers containing C=CH groups and polyesters prepared in accordance with the provisions of this invention are characterized by improved resistance to permeation by water. For purposes of comparison, tests have been conducted upon the interpolymers of:

(A) A mixture of 1'partbyweight'ofstyreneand Z'parts by weight of a polyester 'of propylenefglyfcol'and equal moles of maleic acid'and phthalic'ac'id. This "is a typical commercial interpolymerizable mixture and "is employed as a control.

(B) An interpolymer of approximately 1, part of styrene and 2 parts by weight of a polyester of dihydroxymethyl-xylene and maleic anhydride. 'The polyester of this example was prepared in accordance with the pr0- visions of Example V.

(C) An interpolymer of 1 partby'weight of styrene and 2 parts by Weight of a polyester of maleic anhydride and dihydroxyethoxydimethyl-xylene.

(D) An interpolymer of 1 part by'weight of styrene and 2 parts by weight of a polyester of "maleic anhydride and di beta-hydroxyethoxymethyl xylene.

Moisture tests were conducted by soaking the samples to be tested for a period of 24 hours at 77"F.'and the percentage of water'absorption' was then determined.

The results of the several tests are tabulated as follows:

Percent by weight of water absorbed Interpolymer (A) r 0.30 Interpolymer (B) 0.040 Interpolymer (C) 0.169 Interpolymer (D) 0.094

CH3- X-CHz- It is" to be observed that all'of the 'int'erpolymers of styreneand polyesters derived from maleicacid and a hydroxy derivative of dichloromethyl-xylene are substantially superior and in some instances very superior to the interpolymer'of styreneand the commercial polyester of propylene glycol and equal moles of maleic acid.

Styrene has been referred to as-a monomer suitable for interpolymerization with the polyesters of thisinVen- It may be replaced by other monomers containing C=CH groups attached to negative groups. Examples comprise:

Esters such as- Diallyl phthalate Vinyl acetate Diallyl succinate Diallyl itaconate Amides such as-- Acrylamide Methacrylamide Nitriles such as- Acrylonitrile Hydrocarbons such as- Vinyl toluene Divinyl benzene Monomers may be employed in amounts of 5 to percent by weight based upon the total mixture.

The polyesters of this invention may be mixed with other liquid, soluble polyesters such as those of phthalic acid or adipic acid and alcohols containing two or more hydroxyls, such as:

'Ethylene glycol "Propylene glycol Diethylene glycol Glycerol Pentaerythritol 'The" mixtures may be employed for coatings, for reaction with diisocyanates and the like.

I claim:

1.'As a newmaterial a polyester'of dihydroxymethyl Xylene and maleic acid.

2. As a new material a polyester of dihydroxymethyl xylene and fumaric acid.

3. As a new material a'polyester ofdihydroxymethyl xylene and alpha, beta-ethylenic dicarboxylicacid.

4. As a new material an interpolymer of a'monomcr containing a C=CH group and a polyester as defined in claim 1.

5. As a new material an interpolymerof .a' monomer containing a C=CH group and a polyesteras defined in'claim 3.

6. As anew material a polyester of dihydroxymethylxylene-and an acid of a class consisting of maleic acid and fumaric acid.

7. A polyester of the formula:

CHs- CH CH2 -Z-C-R-COY where X is of a class consistingof halogen and I-IZ, Z being of a class consisting of -O, -OCH CH 0, -O-CH CH CH -O -OCH CH OCH CH -O and p 'OCH CH OCH CH OCHCH -O-- Y being of a class consisting of hydrogen and alkali metal and R being of a class consisting of an ethylenically unsaturated alkylene group, a saturated alkylene group and an arylene group and n is a whole number from about 1- to about 10.

References Cited inthe file of thispatcnt UNITED STATESPATENTS 2,647,099 Smith July 28, .1953 2,806,834 Nischk et al. Sept. 17, 1957 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N00 2,881,150 April 7, 1959 Column 2, line 45, the formula should appear as shown below instead of as in the patent:

column 4, line 6, for "peroxide", second occurrence, read peroxidic column 6, line 42, for "poleyster" read polyester Signed and sealed this 10th day of November 1959.,

(SEAL) Attest:

KARL H, AXLINE Attesting Officer ROBERT C. WATSON Commissioner of Patents 

7. A POLYESTER OF THE FORMULA: 